A JetBlue flight from New York to Las Vegas made an unscheduled landing in Amarillo, Texas, this morning after a man identified by passengers as the captain left the cockpit and then started shouting and pounding on its door before he was restrained.

NBC News reports that “Flight 191, which departed New York’s John F. Kennedy airport at 7:28 a.m. ET, was enroute when the captain began behaving erratically. The co-pilot was able to get the captain out of the cockpit, NBC News reports, but the captain began pounding on the door and was subdued by an off-duty police officer and an off-duty pilot.”

CBS News says it has been told by a federal official that “the captain became incoherent … prompting the co-pilot to get him to leave the cockpit.”

JetBlue, the news network adds, confirms that there was “a medical situation involving the captain.”

At least two videos taken by a passenger have been posted on YouTube already. In one, you can hear some shouting coming from the front of the jet near the cockpit. At one point, a man tells passengers that things are fine — but appears to also say that the man who created the emergency is being restrained.

Earlier this month, an American Airlines flight had to return to its gate in Chicago after a flight attendant “took over the public-address system and launched into a rant that included references to 9-11 and the safety of their plane,” as The Associated Press reported.